Psilocybin, the primary psychoactive compound in several mushroom species (most commonly Psilocybe cubensis), has been the subject of a significant and rapidly expanding clinical research program since the early 2010s. Following decades of restricted research access, the U.S. Food and Drug Administration (FDA) granted Breakthrough Therapy designation to psilocybin for treatment-resistant depression in 2018 and for major depressive disorder in 2019. These designations catalyzed a wave of Phase 2 and Phase 3 clinical trials across North America, Europe, and Australia. This page compiles key statistics on clinical trial activity, published efficacy data, regulatory status, and policy developments from ClinicalTrials.gov, MAPS, PubMed, the New England Journal of Medicine, and government legislative records through early 2026.
Clinical Trial Activity
A search of ClinicalTrials.gov in early 2025 identified more than 100 registered studies involving psilocybin, covering a range of conditions including major depressive disorder, treatment-resistant depression, post-traumatic stress disorder, alcohol use disorder, obsessive-compulsive disorder, anorexia nervosa, and end-of-life anxiety.
— ClinicalTrials.gov, search conducted April 2025As of early 2025, approximately 25 psilocybin trials were listed as actively recruiting participants, with the majority based in the United States, United Kingdom, Netherlands, and Australia.
— ClinicalTrials.gov, 2025The pace of psilocybin research publication has accelerated dramatically. Fewer than 5 human clinical studies involving psilocybin were published per year prior to 2015. By 2022 and 2023, more than 15 peer-reviewed clinical studies per year were indexed on PubMed.
— PubMed database analysis, 2025Compass Pathways (COMP360) conducted the largest psilocybin randomized controlled trial to date, enrolling 233 patients with treatment-resistant depression. Phase 2b results were published in the New England Journal of Medicine in 2022.
— New England Journal of Medicine, 2022; Compass PathwaysPublished Clinical Outcomes
A 2021 randomized controlled trial at Johns Hopkins Medicine, published in JAMA Psychiatry, found that two psilocybin sessions with supportive therapy produced rapid and substantial reductions in depressive symptoms. 71% of participants met the criterion for treatment response, and 54% met criteria for remission at the four-week follow-up.
— Davis et al., JAMA Psychiatry, 2021The Compass Pathways Phase 2b COMP360 trial enrolled 233 patients with treatment-resistant depression. The 25mg psilocybin group showed significantly greater improvement in MADRS (Montgomery–Åsberg Depression Rating Scale) scores at 3 weeks compared to the 1mg control group. 29% of participants in the 25mg arm achieved remission at 3 weeks, versus 8% in the control group.
— Goodwin et al., New England Journal of Medicine, 2022A 2022 trial published in the New England Journal of Medicine comparing psilocybin-assisted therapy directly with escitalopram (a common SSRI) for major depressive disorder found psilocybin produced greater reductions in depression scores at 6 weeks, with comparable safety profiles. The study, conducted at Imperial College London, enrolled 59 participants.
— Carhart-Harris et al., New England Journal of Medicine, 2021Long-term follow-up studies have documented sustained reductions in depression and anxiety scores 12 months after psilocybin-assisted therapy in patients with life-threatening cancer diagnoses, originally published as part of NYU and Johns Hopkins studies in the Journal of Psychopharmacology.
— Agin-Liebes et al., Journal of Psychopharmacology, 2020FDA & Regulatory Status
The FDA's Breakthrough Therapy designation is intended to expedite development and review of drugs that demonstrate substantial improvement over available therapies for serious conditions. Compass Pathways received this designation for psilocybin in treatment-resistant depression in 2018; USONA Institute received it for major depressive disorder in 2019.
— U.S. Food and Drug Administration, 2018, 2019Psilocybin remains a Schedule I controlled substance under the U.S. Controlled Substances Act as of early 2026, meaning the federal government classifies it as having no currently accepted medical use and a high potential for abuse. Clinical research is conducted under DEA Schedule I researcher licenses.
— U.S. Drug Enforcement Administration; Controlled Substances ActAustralia became the first country to formally recognize psilocybin as an approved medical treatment, authorizing psilocybin for treatment-resistant depression effective July 1, 2023. Australian psychiatrists may prescribe it through the Therapeutic Goods Administration's Authorized Prescriber pathway.
— Therapeutic Goods Administration (TGA), Australia, 2023Compass Pathways announced plans to initiate a Phase 3 clinical trial for COMP360 psilocybin therapy in treatment-resistant depression, with a New Drug Application (NDA) filing anticipated in the 2025–2026 timeframe pending Phase 3 outcomes. USONA Institute is conducting a Phase 3 trial (MAPP2) for psilocybin in major depressive disorder.
— Compass Pathways, 2024; USONA Institute, 2024Depression & PTSD Data
Major depressive disorder (MDD) affects an estimated 280 million people worldwide, making it one of the most prevalent and disabling mental health conditions globally. Approximately 30% of patients with depression are classified as treatment-resistant, meaning they do not respond adequately to at least two antidepressant treatments — a population of approximately 84 million people for whom psilocybin research is most relevant.
— World Health Organization, 2023; Journal of Clinical Psychiatry, 2022Post-traumatic stress disorder (PTSD) affects approximately 3.5% of U.S. adults annually, or about 9 million people per year. Psilocybin is being evaluated in multiple clinical trials as an adjunct to psychotherapy for PTSD, with early Phase 2 results expected in 2025–2026.
— National Center for PTSD (VA), 2024; ClinicalTrials.govEnd-of-life anxiety represents a well-researched indication for psilocybin. Meta-analyses of trials at Johns Hopkins and NYU involving cancer patients found significant reductions in both anxiety and depression scores following a single high-dose psilocybin session, with effects persisting through 6-month follow-up assessments.
— Journal of Psychopharmacology, 2016 (Johns Hopkins/NYU meta-analysis)Addiction Research Data
A pilot study at Johns Hopkins, published in Drug and Alcohol Dependence (2014), evaluated psilocybin-assisted therapy for smoking cessation in 15 participants. At 12-month follow-up, 59% of participants remained smoke-free — substantially higher than the 20–35% rates typically reported for other evidence-based smoking cessation treatments.
— Johnson et al., Drug and Alcohol Dependence, 2014A 2022 randomized controlled trial published in JAMA Psychiatry evaluated psilocybin for alcohol use disorder in 93 participants. The psilocybin group showed significantly greater reductions in percentage of heavy drinking days (59.5% reduction) compared to the active placebo group (23.6% reduction) over 32 weeks of follow-up.
— Bogenschutz et al., JAMA Psychiatry, 2022Opioid use disorder represents an emerging research focus for psilocybin. Multiple Phase 2 trials are currently underway examining psilocybin as a treatment adjunct for opioid dependence, motivated by the urgent need for novel approaches to a condition responsible for over 80,000 U.S. overdose deaths annually.
— ClinicalTrials.gov, 2025; CDC, 2024Legalization & Policy Status
Oregon became the first U.S. state to legalize supervised psilocybin services through Measure 109, passed by voters in November 2020. Oregon's regulated service center program became operational in 2023, allowing licensed facilitators to provide psilocybin sessions to adults without a medical diagnosis requirement.
— Oregon Health Authority, 2023Colorado voters passed Proposition 122 in November 2022, legalizing supervised psilocybin services and creating a regulated framework for service centers. Colorado's program began licensing facilitators in 2024.
— Colorado Department of Regulatory Agencies, 2024Several U.S. cities — including Denver, CO (2019), Oakland and Santa Cruz, CA (2019–2020), and Ann Arbor, MI (2020) — decriminalized possession and personal use of psilocybin mushrooms before state-level frameworks existed. These local measures do not create legal commercial access.
— Municipal ordinance records, 2019–2020The United Kingdom does not currently have an approved psilocybin therapy pathway, but the MHRA (Medicines and Healthcare products Regulatory Agency) has permitted clinical research. Several UK universities including Imperial College London and King's College London are active research centers.
— MHRA, 2024; Imperial College LondonResearch Funding & Investment
Private investment in psilocybin research and therapeutics companies exceeded an estimated $200 million between 2020 and 2024. Major publicly traded companies in the space include Compass Pathways (NASDAQ: CMPS), Atai Life Sciences (NASDAQ: ATAI), and MindMed (NASDAQ: MNMD).
— Crunchbase; company investor relations filings, 2024The National Institutes of Health (NIH) awarded its first grants for psychedelic research in decades in 2021, including funding for psilocybin studies through NIDA (National Institute on Drug Abuse) and NIMH (National Institute of Mental Health), signaling growing federal scientific interest.
— NIH Reporter database, 2021–2024The Multidisciplinary Association for Psychedelic Studies (MAPS), a nonprofit research and advocacy organization, has raised over $100 million in cumulative donations and has been instrumental in funding FDA-reviewed psychedelic research since its founding in 1986.
— MAPS Public Benefit Corporation, 2024Frequently Asked Questions
How many clinical trials on psilocybin are currently active?
As of early 2025, more than 100 psilocybin studies were registered on ClinicalTrials.gov, with approximately 25 actively recruiting participants. These trials cover conditions including major depressive disorder, treatment-resistant depression, PTSD, alcohol use disorder, smoking cessation, and end-of-life anxiety, among others.
Has the FDA approved psilocybin for any medical use?
As of early 2026, the FDA has not approved psilocybin for any medical use. Psilocybin remains a Schedule I controlled substance under federal law. However, the FDA granted Breakthrough Therapy designation to psilocybin for treatment-resistant depression in 2018 (Compass Pathways) and for major depressive disorder in 2019 (USONA Institute), which expedites the review process. Phase 3 trials are underway, with NDA submissions anticipated in 2025–2026.
Where is psilocybin legally available for therapeutic use?
Australia became the first country to authorize psilocybin for clinical therapeutic use in July 2023, allowing authorized psychiatrists to prescribe it for treatment-resistant depression. In the United States, Oregon and Colorado have operational regulated service center frameworks at the state level, though psilocybin remains illegal under federal law. Several cities have decriminalized personal possession.
What does the clinical research show about psilocybin's effectiveness for depression?
Published Phase 2 trials show clinically significant reductions in depression scores for both major depressive disorder and treatment-resistant depression. A 2021 Johns Hopkins trial (JAMA Psychiatry) found a 71% response rate and 54% remission rate at four weeks. The Compass Pathways Phase 2b trial (NEJM, 2022) found a 29% remission rate at three weeks in the 25mg arm versus 8% in the control group. A direct comparison with escitalopram (SSRI) published in NEJM found psilocybin produced greater symptom reduction at 6 weeks. Phase 3 evidence is still being generated.
Is psilocybin research being conducted for addiction treatment?
Yes. Psilocybin has been studied for alcohol use disorder, tobacco dependence, and opioid use disorder. A 2022 JAMA Psychiatry trial found the psilocybin group reduced heavy drinking days by 59.5% versus 23.6% in the placebo group over 32 weeks. A Johns Hopkins pilot study found 59% smoking abstinence at 12 months. Multiple Phase 2 trials for opioid use disorder are currently underway.
Sources: ClinicalTrials.gov (April 2025); U.S. Food and Drug Administration (2018, 2019); Davis et al., JAMA Psychiatry (2021); Goodwin et al., New England Journal of Medicine (2022); Carhart-Harris et al., New England Journal of Medicine (2021); Bogenschutz et al., JAMA Psychiatry (2022); Johnson et al., Drug and Alcohol Dependence (2014); Agin-Liebes et al., Journal of Psychopharmacology (2020); World Health Organization (2023); National Center for PTSD, VA (2024); Oregon Health Authority (2023); Colorado Department of Regulatory Agencies (2024); Therapeutic Goods Administration, Australia (2023); MAPS Public Benefit Corporation (2024); NIH Reporter database (2021–2024); CDC (2024); PubMed database (2025).